Solid-state imaging element

Abstract

A solid-state imaging element includes a light-receiving element portion disposed in a semiconductor layer, an insulating layer made of a material having a refractive index n 0 , disposed over the semiconductor layer, and an antenna structure disposed over the light-receiving element portion and surrounded by an insulating layer. The antenna structure is made of a material having a refractive index higher than the refractive index of the insulating layer. The energy of light having entered the antenna structure and the insulating layer is concentrated in the light-receiving element portion.

What is claimed is: 
     
       1. A solid-state imaging element comprising:
 a light-receiving element portion disposed in a semiconductor layer; 
 an insulating layer made of a material having a first refractive index, disposed over the semiconductor layer; 
 a microlens formed over the insulating layer; and 
 an antenna structure disposed over the light-receiving element portion and surrounded by the insulating layer, the antenna structure being made of a material having a second refractive index that is higher than the first refractive index of the insulating layer, 
 wherein the antenna structure has an area that is less than an area of the light receiving element portion, and 
 wherein the energy of light having entered the antenna structure and the insulating layer is concentrated in the light-receiving element portion. 
 
     
     
       2. The solid-state imaging element according to  claim 1 , wherein the antenna structure has a cylindrical shape having a diameter of 0.2 to 0.4 μm. 
     
     
       3. The solid-state imaging element according to  claim 1 , further comprising:
 an insulating interlayer over the antenna structure and the insulating layer, 
 a color filter on the insulating interlayer, wherein the microlens is formed on the color filter. 
 
     
     
       4. The solid-state imaging element according to  claim 1 , wherein the antenna structure has an extension extending from the top thereof in a direction parallel to the surface of the semiconductor layer. 
     
     
       5. The solid-state imaging element according to  claim 1 , wherein the first refractive (n 0 ) and the second refractive index (n 1 ) satisfy the relationship (n 1 −n 0 )≧0.25. 
     
     
       6. The solid-state imaging element according to  claim 1 , wherein the antenna structure has a flat top. 
     
     
       7. The solid-state imaging element according to  claim 1 , wherein the antenna structure is disposed with a distance of 0.2 μm or less between the bottom thereof and the surface of the semiconductor layer. 
     
     
       8. The solid-state imaging element according to  claim 1 , further comprising an antireflection film on the surface of the semiconductor layer, wherein a first surface of the antireflection film is in contact with the surface of the semiconductor layer, and wherein a second surface of the antireflection film is in contact with a surface of the antenna structure. 
     
     
       9. The solid-state imaging element according to  claim 1 , further comprising a light-shielding layer around the antenna structure with the insulating layer therebetween. 
     
     
       10. The solid-state imaging element according to  claim 1 , further comprising a drive circuit driving the light-receiving element portion on a side of the semiconductor layer opposite to the antenna structure. 
     
     
       11. The solid-state imaging element according to  claim 5 , wherein the material of the antenna structure includes at least one selected from the group consisting of silicon nitride, silicon oxynitride, hafnium oxide, and tantalum oxide. 
     
     
       12. The solid-state imaging element according to  claim 5 , wherein the material of the antenna structure includes a transparent dielectric material in which fine particles are dispersed.